1. Field of the Invention
The present invention relates in general to a method of preparing dry transfer sheets or decalcomanias, and more particularly to a simple method suitable for preparing dry transfer sheets for transferring to desired receiving surfaces desired graphic images or indicia such as letters and designs which are printed on carrier sheets.
2. Discussion of the Prior Art
It is known to produce graphic images or indicia such as lettering or graphic designs by transferring the graphic images from a dry transfer sheet or material to a desired receiving surface. A known method for preparing such dry transfer sheets consists in transferring desired graphic images to a suitable carrier sheet, for example by screen-printing with an ink material. Usually, an adhesive coat is applied to cover the transferred indicia on the carrier sheet, by a printing, spraying, wire-bar technique. Thus, the dry transfer sheet is prepared. With an action of the adhesive coat, the selected indicia can be transferred from the dry transfer sheet and adhered to the desired receiving surface. Such types of dry transfer sheets or materials, or adhesive transfers have been proposed, for example, in British Patent Specifications Nos. 954459, and 959670.
The method of producing the dry transfer sheets of the type indicated above requires the use of a screen-printing machine, and the preparation of printing plates carrying desired indicia, silk screens, or similar printing equipment and tools. The practice of such a printing method needs a large amount of investment in the equipment, and a considerably long time.
Therefore, the users who can not afford such substantial amounts of expense and time must buy commercially available dry transfer sheets which carry printed graphic images or indicia. In this instance, the users are sometimes or frequently forced to buy the dry transfer sheets which include letterings and/or graphic designs other than those which are not desired or needed by the users. Since the undesired indicia remain unused, the cost of transfer per character, for example, is relatively high. If the users require special images of their own choice, they often cannot find their desired images on the commercially available dry transfer sheets. If the images to be transferred consist of a word, phrase or sentence, for instance, the users are required to individually transfer the corresponding letters from a transfer sheet or sheets, one after another, while registering the transferred letters. This procedure is very cumbersome and time-consuming, particularly when a complicated layout or neat arrangement of the letters is desired.
In recent years, photbgraphic methods of producing dry transfer sheets or materials have been proposed, in place of the printing method described above. For example, the methods are, disclosed in British Specifications Nos. 1079661, 1291960, 1364627 and 1441982. In such a proposed photographic method, a light-sensitive sheet is image-wise photographically exposed in conjunction with an original constituting a master of desired indicia such as letters and designs. The exposed light-sensitive sheet is then separated from the original and subjected to a developing process, whereby a dry transfer sheet consisting of the developed sheet as an image-carrier sheet is produced.
However, the photographic method including exposing and developing steps requires exposing and developing devices, and consequently needs considerable amounts of investment and time, though the amounts are less than those required for the screen-printing method stated above. In this case, too, the users are required to buy commercially available transfer sheets, and the same disadvantages described above are more or less encountered. In particular, if the user requires specific indicia of his own choice of color and design in relatively small numbers, the photographic method is not justifiable.